Low visual impact labeling method and system

ABSTRACT

A method of forming symbols, characters, and other images from a light polarizing material including machine readable indicia enabling automated identification of articles is disclosed. A light polarizing material is applied over a reflective layer in a machine readable pattern. The material may be an image imprinted on a label with a light polarizing material on a substrate such as a transparent oriented film. In one aspect, a mail processing system includes a computer including a database of destination codes corresponding to a plurality of mail pieces for delivery to at least some of the destination codes. A media applicator utilizes the database for generating and applying a light polarizing material to a label or article to form a machine readable indicia, including the destination code for each of the plurality of mail pieces. A mail sorting system utilizing the label includes a camera with polarized lenses for filtering light reflected from indicia formed from a light polarizing material on the label. A detector associated with each of the lenses for detecting reflected light and generating a signal in response thereto. Signals from the detector are compared by a computer that produces an electronic image or pattern corresponding to the machine readable indicia and generates a sorting signal based upon the indicia which is transmitted to a mail sorter where the mail pieces are sorted.

This application is a division of U.S. patent application Ser. No.10/033,735, filed Dec. 20, 2001 which claims priority based on U.S.Provisional Patent Application Ser. No. 60/258,986, filed Dec. 29, 2000.

TECHNICAL FIELD

The present invention relates to the field of article identificationmethods and systems, and particularly to a label, system and method thatprovides a means of coding articles for identification, sorting andprocessing with minimal visual impact.

BACKGROUND OF THE INVENTION

The system and method according to the invention may be advantageouslyapplied in a variety of contexts where it is desired to label articlesfor identification with minimal impact on the appearance of thearticles, for example items that have been specially wrapped forpresentation, articles having critical information printed on anexterior surface, decorative items and the like. Another application inwhich the system and method of the invention may be advantageouslyutilized is in connection with mail piece labeling for automatedprocessing.

Modem postal services, for example, the U.S. Postal Service, handlemassive volumes of mail pieces on a daily basis. Consequently, automatedhandling and sorting equipment is employed whenever and whereverpossible to facilitate the sorting, processing and distribution of mailpieces. Such systems have been proven extremely effective in sortinglarge volume mail flows, but these systems have limitations. Thesesystems may use either optical character recognition (OCR) technology torecognize the addresses or codes placed on the envelopes, or may userelatively simple scanners to scan a machine readable code such as a barcode which has been recorded or applied to each mail piece. The OCR/CSsystem often includes a printer for printing bar-code formatted ZIPcodes (or similar codes) on envelopes or on labels applied to mailpieces so that each mail piece might be further sorted at local stationsmore efficiently. Typically, the mail pieces are coded and sortedaccording to a sort scheme into numerous groups (e.g. a range of ZIPcodes, ZIP code (5 digits), ZIP code (9 digits), etc.).

Facilitating the delivery of certain types of mass mailings is theprocess of presorting. A substantial percentage of the mail the USPSdelivers on a regular basis consists of mass mailings. These massmailings typically consist of advertisements, promotional materials,solicitations, bills and similar materials. Such mailings are printed,addressed or labeled in accordance with a presort scheme to aid indelivery of the mailings and/or presorted in some cases down to thedelivery point. The presort scheme is normally by destination addressand the mailings are presented to the national postal serviceaccordingly. In many cases, the presort operation includes labeling oraddressing the mail pieces with bar coded information such as the ZIPplus four code to facilitate down stream processing. Presort mailingoften includes catalogues, brochures, magazines and similar items.

Automated processing of presorted flats, such as magazines andcatalogues presents certain mechanical and imaging problems notencountered in connection with automated processing of letters. Althoughin many cases these mail pieces will have a user-applied postnet barcode, problems are often encountered in locating the coded region ofinterest (ROI) on the cover of the flat. These problems include poorcontrast ratios and partial obscuration due to printed backgrounds,label skew (rotation from horizontal or vertical alignment), and thelarge amount of printed information which often appears on the covers,including text and other bar codes, which tends to confuse high-speedalgorithmic approaches to ROI finding.

A solution for a portion of the mail stream is for the postal service toapply conventional paper labels on which a conventional bar code is thenprinted, thus ensuring consistent placement and, if necessary, the useof visual keys. However, a large percentage of the volume of flat mailconsists of magazines and catalogues for which this is not a goodsolution.

Publishers of magazines, catalogues, brochures and similar articlesintended for mail delivery often spend large sums on the design, layoutand content of the covers of such publications in order to achieve thedesired visual impact on the recipient. High quality paper, elaboratedesign, layout and expensive reproduction techniques escalate the costof catalogues and brochures that may be summarily discarded by therecipient. In many instances, the initial reaction of the recipient tothe cover of a catalogue or similar publication will determine whetherthe recipient keeps the catalogue for further examination or immediatelydiscards it as he or she sorts through that day's mail. If the visualappearance is degraded or the publisher's message is partially obscuredby a label, the value of the mailing is reduced. Consequently, there isa great deal of resistance on the part of the distributors of suchcatalogues and magazines to any printing or labeling of the publicationscover that might tend to detract from the cover's appearance and itsvisual impact on the consumer. Thus, the publishers and distributors ofmagazines, catalogues and brochures intended for mail delivery generallyobject to labeling of the cover of these publications with a typicalprinted stick-on bar coded label of the type used by postal and deliveryservices to aid in processing and sorting mailed items.

Attempts to use fluorescent inks have met with little success due toproblems with long drying times for such inks, smearing of the ink andpoor contrast ratios with respect to the underlying substrate. Thelatter problem is associated with papers having high fluorescence, i.e.,recycled papers.

Thus there exists a need for a label and system that allows the use oftechniques and processes for automated labeling and identification ofarticles designed to convey a distinct visual impression. This isparticularly true of catalogues, magazines, brochures and similarpublications intended for mail delivery where a system and method thatallows information to be coded onto the publication with minimal visualimpact on the cover of the publication would be highly desirable. Theinvention addresses this need with a label and labeling system having aminimal optical impact and reading system capable of reliably readingthese labels.

SUMMARY OF THE INVENTION

The invention provides a method for identifying articles includinglabeling the articles with a light polarizing material, the lightpolarizing material forming a machine readable indicia including a codefor automated identification of the article. The light polarizingmaterial is applied over a second, reflective material that reflectslight through the light polarizing material to create or form an imagefrom which the machine readable indicia may be reproduced. The image isreproduced by splitting, filtering and transmitting the reflected lightto detectors that produce a plurality of electronic images which arecompared by subtracting pixels.

In one aspect, the method further includes utilizing a data baseincluding a plurality of codes to apply a different machine readableindicia to different ones of the plurality of articles. Particulararticles may be identified in this manner based upon the machinereadable indicia applied to the article which corresponds to one of theplurality of identification codes.

In another aspect, a machine readable indicia is formed on a pluralityof labels from a light polarizing material applied over a reflectivematerial that reflects light through the light polarizing material thatcan be filtered to produce a plurality of images. The machine readableindicia is reproducible by electronically comparing the images. Thelabels are applied to articles thereby enabling automated identificationof the articles.

In this respect, automated identification of the articles includes (1)exposing the machine readable indicia to a source of light, (2) dividinglight reflected from the indicia into a plurality of beams, (3)filtering each of a plurality of the beams through a polarized filteroffset from each of the other filters by a predetermined angle, (4)generating an electronic image from each of the filtered beams with adetector, and (5) comparing at least one of the electronic images to atleast one other of the electronic images to reproduce an imagecorresponding to the indicia. In yet another aspect, the lightpolarizing material and the reflective material are transparent tovisible light to minimize the visual impact of the label on the article.

In yet another aspect, a labeling system according to the inventionincludes a plurality of labels including a machine readable indiciarepresenting a unique code formed from a light polarizing material andwherein each of the labels includes a reflective layer and a substrate.The system includes a labeler for applying the labels to each of aplurality of articles whereby articles are uniquely identified with oneof the codes. The codes are incorporated into database on a computerthat represents the plurality of articles and in which the unique codefor each of the labeled articles is stored. In one aspect the systemincludes a media applicator for applying a light polarizing material ina machine readable format to the substrate. Preferably, the applicatoris a printer and the light polarizing material is a dichrotic ink.

In yet another aspect, an automated article sorting system according tothe invention includes a plurality of polarized lenses for filteringpolarized light reflected from a label including machine readableindicia comprising a polarized material on the surface of an articleconveyed past the lenses. A detector is provided for each of the lensesto detect reflected light transmitted through the polarized lens,creating an electronic image. The detector sends the signal to acomputer that compares the signals from the detectors to reproduce apattern corresponding to the machine readable indicia. The computergenerates a sorting signal corresponding to the indicia that istransmitted to a sorter that sorts the articles based upon the signalreceived from the computer.

In a preferred embodiment, each of the detectors is a charged coupledarray that generates a digitalized electronic image from reflected lightpassing through one of the filters. Each of the digitalized images arecompared by the computer on a pixel-by-pixel basis to at least one otherdifferent digitalized image to reproduce the machine readable indicia.

The invention is particularly applicable to mail piece identificationand handling. In this regard, the invention provides a method foridentifying a mail piece by applying a machine readable indicia to themail piece, the indicia including a destination or other code andoptionally other printed information. The machine readable indicia isformed from a polarizing material with a reflective layer providedbeneath the polarizing material to reflect polarized light back throughthe indicia, the reflected light comprising a machine detectable patternincluding the printed code and/or other information. The method may alsoinclude the steps of (a) utilizing a data base including destinationcodes to apply the machine readable indicia to a plurality of mailpieces (b) preprinting a plurality of labels with a light polarizingmaterial utilizing the database, the labels including a reflective layerfor reflecting polarized light and wherein the reflected light comprisesa machine detectable pattern corresponding to an entry in the data baseand thus inferentially to the destination code of a mail piece.

In this regard, the labels are exposed to a light source and thereflected light is separated with a beam splitter into a plurality ofbeams. Each of the plurality of beams is directed through a polarizedfilter and each filter is rotated with respect to each of the otherfilters by a predetermined angle, for example 60°. A detector such as acharged coupled array is used to generate an electronic image from eachof the filtered beams and the electronic images are then compared toeach of the other electronic images to isolate the image reflected fromthe indicia. In mail processing applications, the machine readableindicia may be a bar code such as Post Net code or a similar codeincluding destination information for the mail piece. The system mayalso utilize materials which function as indicated only in infra-red orultra-violet light so that the indicia and/or the substrate may betransparent to visible light, further reducing the visual impact of theindicia relative to the cover of the mail piece.

In yet another aspect, the invention provides a mail processing systemcomprising a computer including a database of destination codescorresponding to a plurality of mail pieces for delivery to at leastsome of the destination codes. A media applicator coupled to thecomputer utilizes the database for generating machine readable indiciain the form of a light polarizing material, including the destinationcode for each of the plurality of mail pieces. The media applicator maybe a printer wherein the machine readable indicia is imprinted with adichroic ink on a label. The indicia may be also preprinted on labelswhich are then applied to the mail pieces with a label applicator.Alternatively, the label may be applied to the mail piece prior toprinting.

The invention also provides a mail sorting system including a pluralityof polarized lenses for filtering polarized light reflected from amachine readable indicia formed from a light polarizing material. Adetector, such as a charge coupled array, is associated with each of thelenses for detecting reflected light and generating a signal in responsethereto. The signal is an electronic image of the mail piece using aselected bandwidth of light as viewed through the associated polarizingfilter in the form of digitized electronic pixels. The signals from thecharge coupled array are transmitted to a computer which compares theelectronic images to detect a pattern corresponding to the machinereadable indicia. In one embodiment, the computer creates threedifferent images by subtracting the electronic pixels forming each imagefrom the electronic pixels forming each of the other images. Theclearest differential image may then be selected. Based upon the imageof the indicia produced by the subtraction, the computer then generatesa sorting signal corresponding to the indicia which is transmitted to amail sorter where the mail pieces are sorted based upon the informationcontained in the indicia, for example, by destination code.

These and other advantages and features of the invention will be readilyapparent from the following Detailed Description and Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is a top view of a mail piece bearing a label in accordance withthe invention including machine readable indicia in the form of a barcode;

FIG. 1(a) is a cross section view of the mail piece and label of FIG. 1taken along lines a-a of FIG. 1;

FIG. 2 is a schematic diagram of a system for identifying mail piecesutilizing one embodiment of a method of the invention;

FIG. 3 is a schematic of a system for sorting mail pieces utilizing thelabel and method of the invention;

FIG. 4 is a schematic diagram of an alternate system for identifyingmail pieces according to the invention;

FIG. 5 is an illustration of a magazine cover bearing a label of thetype of the invention;

FIGS. 6 a-6 c illustrate images of the magazine cover formed from lightreflected from the cover and filtered through polarizing filters;

FIGS. 7 a-7 c illustrate images formed by comparing electronic imagescorresponding to FIGS. 6 a-6 c and subtracting pixels of the images; and

FIGS. 8-11 illustrate images of the magazine cover as filtered andcompared in which the effect of variations in parameters are shown.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention. In particular, while the invention is described in thecontext of mail piece identification and processing, it will beappreciated that the method and system described herein may be utilizedin numerous other applications where it is desired to label items forthe purposed of identification with minimal impact on the appearance ofthe article.

Sunlight and most forms of artificial light are electromagnetic waveswhose electric field vectors vibrate in all perpendicular planescontaining or orthogonal to the vector which indicates the direction ofpropagation. When the electric field vectors of such radiation arerestrained to a single plane, the light is said to be polarized relativeto the direction of propagation and the electric field waves vibrate inthe same plane. Light may be polarized to a certain degree when it isreflected from a surface such as water or a highway. In this case, lightwaves that have electric field vectors parallel to the reflectingsurface are reflected to a greater degree than those with differentorientations. Light may also be polarized through the use of certainfilters. In one aspect, the invention takes advantage of the propertiesof light, in particular polarization, to provide a label and system forcoding mail pieces and in particular pieces such as magazines,catalogues, brochures and similar items with a machine-readable code ina form that minimizes the visual impact of the label on the appearanceof the cover of the publication.

Referring now to FIGS. 1 and 1(a) there is illustrated a portion of amail piece 10 such as a catalogue or magazine cover with a label 12according to the invention applied thereto. In one embodiment, the labelis formed from a non-opaque material such as a transparent polymer.Preferably, the label is formed from an oriented film such that adichroic ink will form a polarized image on or in the film. “Dichroic”as used herein refers to the characteristic of differential absorptionof incident radiation in the visual, UV, and IR spectrum depending uponthe direction of vibration of the electromagnetic waves comprising theradiation. A “Dichroic ink” refers to an ink containing a dye or stainhaving molecules that tend to align with the molecules of a substrate,such as an oriented film, resulting in a substrate that will selectivelyabsorb differently polarized components of an incident light beam. Suchinks and techniques for applying such inks are known, for example U.S.Pat. No. 6,013,123 issued Jan. 11, 2000 to Scarpetti for “Inking Methodsand Compositions for Production of Digitized Stereoscopic PolarizingImages” discusses the use and application of inks containing a dichroicdye, water and a humectant. Also, as used herein the term “light”encompasses radiation in the visible spectrum (“visible light”) as wellas non-visible UV and IR radiation.

As illustrated the label comprises a machine-readable indicia 14, inthis case a bar code printed with a dichroic ink. Alternatively, theportion 16 of the label 12 excluding bar code 14 may be printed with adichroic ink, leaving the bar code as an unpolarized area. Positionedbetween label 12 and indicia 14 is a reflective layer 18 which asillustrated is coextensive with indicia 14 or, alternatively, with thelarger surface 16.

The purpose of reflective layer 18 is to reflect incident light so as toprovide sufficient contrast for the machine readable indicia 14. Thedegree of opaqueness of reflective layer 18 is preferably maintained ata level sufficient to reflect enough light to contrast bar code 14 forthe purpose of scanning as hereinafter described, while transmitting asmuch light as possible to minimize the visual impact of the label.Depending upon the particular application, reflective layer 18 may beformed from a number of known materials capable of reflecting light inthe spectrum of interest, including light in the visible spectrum,infrared or near infrared and ultraviolet. For example, the reflectivelayer may be a plastic film including one or more additives that modifythe optical properties of the film such that the desired spectrum isreflected from the film. In other applications, a metalized layer formedwith known methods of applying an extremely thin layer of metal to asubstrate such as plastic may be used. A metalized layer would beparticularly suitable for labeling gift and decorative items coveredwith a metallic foil or where a metallic foil is used to protect an itemfrom sunlight. In other applications the reflective layer may be silicaor a similar material incorporated into a plastic film

In one preferred embodiment, reflective layer 18 is partiallytransparent to visible light, thereby minimizing the visual impact ofthe label. The term “partially transparent” as used herein refers to thecapability of a material to pass sufficient visible light to enablenormal visual recognition of an underlying image. Thus, “partiallytransparent” may encompass materials allowing differing degrees of lighttransmission depending upon the particular application. While atranslucent or partially transparent reflective layer 18 is preferable,it is not required for all applications. In some applications it may bedesirable for reflective layer 18 to be opaque and colored to match anunderlying surface and/or be coextensive with the entire area of label12.

In one preferred embodiment, label 12 is formed from an orientedtransparent plastic film with a transparent or translucent reflectivelayer 18 printed or applied to the label 12. Machine readable indicia 14is formed from a dichroic dye which is preferable fully transparent tovisible light and constitutes a polarizing filter in the UV or IRwavelengths of light. In this case, the reflective layer 18 is formedfrom a material that is transparent to light in the visible spectrum(“visible light”) while reflecting light in the non-visible UV or IRspectrum. In this embodiment the visual impact of the label 12 upon theoverall appearance of the labeled article is minimized.

Referring now to FIG. 2, an apparatus 20 for preparing and applyinglabels according to the invention includes an applicator 22 whichapplies a reflective layer 18 (FIGS. 1 and 1 a) onto an oriented film 26fed from roll 28. In one embodiment, film 26 has been perforated alonglines defining individual labels and an adhesive coating or layer hasbeen applied to one side of the film for adhering the labels to an itemor article to be labeled. After reflective layer 18 has been applied tothe film, the film is then conveyed through a printer 30 that applies abar code or other machine readable indicia 14 (FIGS. 1 and 1 a)representing a unique numeric or alpha numeric code to the label using adichroic ink. One or more heaters 25 may be used to dry or cure thereflective layer as well as the ink. Heaters 25 may be forced air orradiant heaters depending upon the particular design and application.After printing and curing, the preprinted labels are re-wound into aroll 32 on winder 33 for subsequent use.

Film 26 comprising preprinted labels 34 is fed to a labeling machine 36from roll 32 along with a singulated stream of mail pieces 10.Destination information for each of mail pieces 10 has been acquired byreference to a mailing list for the mail pieces, scanning the mailpieces for previously applied destination information, manual input ofdestination information or a combination of thereof and stored oncomputer 40. The codes previously applied to labels 34 have also beentransferred to and stored on computer 40. As the mail pieces 10 are fedthrough labeling machine 36 a label having a unique code as previouslydescribed is applied to the mail piece and the code is associated withthe record stored in computer 40 for that particular mail piece. Thus,the mail pieces can subsequently be identified, sorted and processedusing the code imprinted on labels 34 along with the record of the mailpiece stored on computer 40. As will be appreciated, in this respect theinvention may be particularly advantageous for use by mailers and/orpresorters of magazines, brochures, catalogues and similar items havingcovers designed to convey a distinct visual impact.

Turning now to FIG. 3, a sorting apparatus 41 for scanning and sortingmail pieces labeled as described above is illustrated. A stream ofsingulated mail pieces is fed from feeder 42 to conveyor 44 forprocessing in accordance with the invention. The location of the mailpieces on the conveyor may be monitored with one or more photocells (notshown) or by other conventional means so as to produce a signal fortransmission to computer 40 for use in further processing of the mailstream. Additionally, an edger (not shown) may be incorporated into theapparatus 41 to ensure proper placement of the mail piece to enablescanning as hereinafter described.

Singulated mail pieces 10 pass under light source 46 which directs abeam 48 of non-polarized visible or invisible, e.g., near-infrared lightonto the mail piece 10. Depending upon the reflective nature of thesubstrate, the illumination is chosen to be diffuse or beamed. Reflectedlight 50 from the mail piece 10 travels to camera 52 which includes oneor more dividers such as beam splitters to generate three machinedetectable beams 54 which are each directed to polarized filters 56. Theaxis of each of polarized filters 56 is rotated sixty degrees (60°)relative to the axes of each of the other filters. The filtered beams 58are directed to impinge upon a detector 60 such as a charge coupledarray (CCD). Each of the charge coupled arrays generates a digitizedelectrical image of the mail piece 10 from the filtered beam 58 andtransmits the electronic image 62 to a computer 64.

Computer 64 receives the electronic images 62 from each of the chargecoupled arrays and compares the images. In one embodiment, computer 64compares the images 62 by subtracting one image from another on apixel-by-pixel basis. Ideally, when an un-polarized image is subtractedfrom another un-polarized image of the same subject, the resulting imagewill be completely black. Thus, when an unlabeled mail piece passesunder the camera or scanner 52 the resultant electronic images 62 areall identical and the resulting combined electronic images will beentirely black.

However, when a mail piece bearing a label according to the inventionpasses under the scanner 52, the image of the polarized area of thelabel 12, as observed via filtered beams 58, will depend upon thealignment of the polarized portion or indicia 14 with respect to theaxis of each of the polarized filters 56. Computer 64 will thereforegenerate up to three images from the three electronic images 62 in whichthe polarized portion of the label 12 will appear white or nearly white,while the remainder of the image will be black. Computer 64 may beprogrammed to select the better images, combine images or other wisemanipulate the images to create a high-contrast image.

After computer 64 has subtracted the digitalized images, the result isan image in which the barcode or indicia 14 will appear white against ablack background. In practice, minor misalignments and variations due tothe application procedure, focusing and camera element alignment areobserved. However, the high contrast white image against the backgroundof black is sufficient to overcome such variations for the purpose ofreading the indicia. Once the machine readable indicia 14 has beenisolated as set forth above, the computer 64 may electronically scan orprocess the indicia using known techniques and read the printed code 14for the particular mail piece 10. Computer 64 then uses this informationand a data base associating this code with a destination to send asorting signal or information corresponding to the mail piece to a downstream conventional mail sorter or sorting equipment 66, where the mailpieces 10 may be sorted by destination code or other criteria, with orwithout mail pieces originating from other sources, depending upon theparticular application.

Referring now to FIG. 4, there is illustrated an alternate system 70 forapplying labels in accordance with a method of the invention to aplurality of mail pieces such as magazines, brochures or catalogues.Feeder 72 feeds a stream of singulated mail pieces 10 onto conveyor 74.The location of the mail pieces on the conveyor may be monitored withone or more photocells (not shown) or by other conventional means so asto produce a signal for transmission to computer 76 which controls theprocess. A label applicator 78 applies a label, for example a piece oforiented transparent polymer film with a pre-applied adhesive, to eachof the mail pieces 10 as the mail pieces are conveyed though the system70. In order to ensure placement of the label in the desired position,the mail piece may be edged, as is known in the art with an edger (notshown). As the mail pieces travel down the conveyor 74, a reflectivelayer 18 (FIGS. 1 and 2) is applied to the label, by for example,printing the layer 18 onto the label with a first media applicator 78.As will be appreciated, the reflective layer 18 could have beenpreviously applied to the label film, in which case, this operationcould be eliminated.

As the mail pieces travel further, a second media applicator 80 appliesa machine readable indicia 14 (FIGS. 1 and 2), by, for example, printingthe indicia 14 over the reflective layer 18 with a dichroic ink. Themachine readable indicia may include a destination code for theparticular mail piece or some other code, symbols, or text to be used insubsequent handling or processing. A computer 82, including a database84 controls the operation of the second media applicator 80, supplingthe destination code from data, for example, a mailing list, stored indatabase 84. In an alternative embodiment, second media applicator 80may comprise a laser or UV light source, the light source imprinting apolarized or non-polarized indicia on a pre-sensitized or treated filmlabel. In the case of a pre-sensitized polarized film, the light sourcemay depolarize an area of the label corresponding to a machine readableindicia. In the alternative, the pre-treatment of the film may allow thelaser to selectively polarize areas of the label corresponding to adesired indicia.

Following application of a machine readable indicia 14 upon the label12, the mail pieces 10 are transported for further processing, forexample stacking and bundling with stacker 66. The labeled mail piecesmay then be transported to a postal service sorting system which may usea scanning apparatus of the type described herein to readily sort themail pieces 10 for delivery based upon the destination code printed onthe label.

As will be appreciated, numerous variations and permutations of theabove-described process may prove advantageous. In the case where theaddress of the recipient is printed upon the mail piece, and an opticalcharacter scanner (OCR) may be used to read the information which couldthen be transmitted to the computer 82 for labeling purposes. It is alsoanticipated that the reflective layer could be pre-applied to the labelfilm, or during production of the film.

As will be appreciated, variations on the above system may be readilydiscerned. For example while the system is described as having a lightdivider that directs beams to a plurality of filters, multiple camerasmay be used with different filters and filter configurations to producethe same result. Similarly purpose-built electronics and/or multiplecomputers or microprocessors may be employed to perform the variousfunctions described above. These and other combinations and permutationsare within the scope of the invention.

In order to fully illustrate the principles of the invention, referenceis now made to FIGS. 5-11. Turning first to FIG. 5 there is shown thecover of a popular magazine as would be perceived by the human eye,including label 12. FIGS. 6 a, 6 b and 6 c correspond to the images asthe images are captured by each of three 2048 pixel (from left to right)charge coupled arrays. As shown, the images are nearly identical exceptthat the image of the bar code varies in brightness between the images.FIGS. 7 a, 7 b and 7 c are the result of digitally subtracting each ofthe images of FIGS. 6 a, 6 b and 6 c from each other, i.e., 6 a-6 b, 6a-6 c and 6 b-6 c. In each of the images presented in FIGS. 7 a-7 c, theonly non-black portion of the image is the bar code and the brightnessof the code in each of the images is a function of the brightness of theimages in the particular pair of subtracted images. In operation, it isanticipated that all three images will be generated with one beingselected for reading based upon its relative brightness.

FIGS. 8-11 illustrate anticipated deviations from the ideal. FIG. 8shows the effect of a one-pixel shift horizontally combined with aone-pixel shift vertically to simulate the translational misalignment oftwo charge coupled arrays. FIG. 9 illustrates the anticipated effect ofa small rotational misalignment with the arc of the misalignmentcorresponding to a shift of one pixel at a corner of the image. FIG. 10shows the anticipated effect of a possible scaling error resulting fromone of the charged coupled arrays observing a slightly larger image,i.e., 2 pixels along the horizontal axis, than observed by the othercharge coupled arrays. FIG. 11 illustrates the image resulting from acombination of the misalignments shown in FIGS. 8-10. As illustrated,while some of the background is not entirely black, the degree ofcontrast is still sufficient to enable scanning and reading the label.Thus, the label and system of the invention are capable of toleratingminor variations that may be encountered in manufacturing, imprintingand scanning operations without affecting the operation of the system.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

1. A labeling system comprising: a plurality of labels including amachine readable indicia representing a unique code, each of the labelsfurther comprising a reflective layer and a substrate, and wherein themachine readable indicia comprises a light polarizing material; alabeler for applying the labels to each of a plurality of articleswhereby articles are uniquely identified with one of the codes; and acomputer including a database representing the plurality of articles,and wherein the unique code for each of the labeled articles is stored.2. The system of claim 1 further comprising a media applicator forapplying a light polarizing material in a machine readable format to thesubstrate.
 3. The system of claim 2 wherein the media applicator is aprinter and the light polarizing material is a dichroic ink.
 4. Thesystem of claim 1 wherein the machine readable indicia is a bar code. 5.The system of claim 4 wherein the bar code is a post net code.
 6. Thesystem of claim 1 wherein the label is oriented polymer film.
 7. Thesystem of claim 6 wherein the film is transparent.
 8. The system ofclaim 3 wherein the dichroic ink is transparent to visible light andforms a polarizing filter for non-visible light in one of the UV and IRwavelengths.
 9. The system of claim 8 wherein the reflective layer isformed from a material that is transparent to light in the visiblespectrum and reflects light in one of the non-visible UV and IRspectrums.
 10. A labeling system for applying a machine readable code toa plurality of mail pieces comprising: means for storing datacorresponding to a plurality of mail pieces, the data comprisingdestination information for each of the mail pieces; means forimprinting a code corresponding to the destination information for theplurality of mail pieces on a plurality of labels, the code comprising alight polarizing material; and means for applying the labels to the mailpieces.
 11. The system of claim 10 further comprising means for applyinga light reflective layer to the labels.
 12. The system of claim 10further comprising means for feeding the mail pieces in a singulatedstream to the means for applying the labels to the mail pieces.
 13. Thesystem of claim 12 further comprising means for determining the positionof each of the mail pieces relative to adjacent mail pieces.
 14. Thesystem of claim 14 further comprising means for stacking the mailpieces.
 15. The system of claim 10 wherein the code comprises a barcode.
 16. The system of claim 16 wherein the bar code comprises a postnet code.
 17. A system for applying a machine readable destinationinformation to a plurality of mail pieces comprising: means for storingdata corresponding to each of a plurality of mail pieces; means forapplying a reflective layer to each of the mail pieces in a selectedlocation on the mail piece; and means for printing a code correspondingto the data stored for each of the plurality of mail pieces on thereflective layer after the layer has been applied to the mail piece, thecode comprising a light polarizing material.
 18. The system of claim 17wherein the code comprises destination information for each of the mailpieces.
 19. The system of claim 17 wherein the light polarizing materialcomprises a dichroic ink.
 20. The system of claim 17 further comprisingmeans for feeding a singulated stream of mail pieces to the means forapplying a reflective layer.